Spina bifida

Introduction

Spina bifida is when a baby's spine and spinal cord don't develop properly in the womb, causing a gap in the spine.

Spina bifida is a type of neural tube defect. The neural tube is the structure that eventually develops into the baby's brain and spinal cord.

The neural tube starts to form in early pregnancy and closes about four weeks after conception.

In spina bifida, part of the neural tube doesn't develop or close properly, leading to defects in the spinal cord and bones of the spine (vertebrae).

It's not known what causes spina bifida, but a lack of folic acid before and in the early stages of pregnancy is a significant risk factor.

Types of spina bifida

There are several types of spina bifida, including:

myelomeningocele – is the most severe type of spina bifida; the baby's spinal canal remains open along several vertebrae in the back, allowing the spinal cord and protective membranes around it to push out and form a sac in the baby's back

meningocele – is another serious type of spina bifida where the protective membranes around the spinal cord (meninges) push out through the spine; the spinal cord usually develops normally so surgery can often be used to remove the membranes without damaging the nerves

spina bifida occulta – is the most common and mildest type of spina bifida; one or more vertebrae don't form properly but the gap in the spine is very small; spina bifida occulta doesn't usually cause any problems and most people are unaware that they have it

These pages focus on myelomeningocele, the most severe type of spina bifida and this is the type referred to whenever the term spina bifida is used.

In most cases of spina bifida, surgery can be used to close the opening in the spine. However, the nervous system will usually already have been damaged, which can lead to problems such as:

weakness or total paralasis of the legs

bowel incontinence and urinary incontinence

loss of skin sensation in the legs and around the bottom - the child is unable to feel hot or cold, which can lead to accidental injury

Many babies will have or develop hydrocephalus (a build-up of fluid on the brain), which can further damage the brain.

Most people with spina bifida have normal intelligence, but some have learning difficulties.

Causes of spina bifida

The cause of spina bifida is unknown, but a number of factors can increase the risk of a baby developing the condition, including:

low folic acid intake during pregnancy

having a family history of spina bifida

medication - taking certain medications during pregnancy has been linked to an increased risk of having a baby with spina bifida

Diagnosing spina bifida

Most cases of spina bifida are detected during the mid pregnancy anomoly scan, which is offered to all pregnant women between 18 and 21 weeks of pregnancy.

If tests confirm that your baby has spina bifida, the implications will be discussed with you. This will include a discussion about the possible problems associated with the condition, the treatment and support your child may need if you decide to continue with the pregnancy, and what your options are regarding ending the pregnancy, if that is your choice.

Tests after birth

Once the baby is born, a number of tests may be carried out to assess the severity of the condition and help decide which treatments are appropriate.

Tests may include:

monitoring your child's head growth and carrying out a brain scan, using an ultrasound scan, CT scan or MRI scan, to check for hydrocephalus (excess fluid on the brain)

In most cases, surgery to repair the spine will be recommended soon after your baby is born.

Treating spina bifida

Treatments for the symptoms or conditions associate with spina bifida include:

surgery soon after birth to close the opening in the spine and treat hydrocephalus

therapies to help may day-to-day life easier and improve independence, such as physiotherapy and occupational therapy.

assistive devices and mobility equipment, such as a wheelchair, or walking aids

treatments for bowel and urinary problems

With the right treatment and support, many children with spina bifida survive well into adulthood. It can be a challenging condition to live with, but many adults with spina bifida are able to lead independent and fulfilling lives.

Preventing spina bifida with folic acid

The best way to prevent spina bifida is to take folic acid supplements before and during pregnancy.

Folic acid recommendations

You should taka a 400 microgram folic acid tablet every day while you're trying to get pregnant and until you're 12 weeks pregnant.

If you didn't take folic acid before you conceived, you should start as soon as you find out you're pregnant.

Folic acid tablets are available from pharmacies and supermarkets, or your GP may be able to prescribe them for you.

You should also try to eat foods than contain folate (the natural form of folic acid), such as broccoli, spinach and chickpeas.

Recommendations for women at higher risk of spina bifida

Women thought to be at higher risk of having a child with spina bifida need to be prescribed a higher (5 milligram) dose of folic acid by their GP.

Women at higher risk include those:

with a family history of neural tube defects

with a partner with a family history of neural tube defects

who've had a previous pregnancy affected by a neural tube defect

with diabetes

Your GP can advise you further about this.

If you're taking medication to treat epilepsy, you should consult your GP for advice. You may also need to take a higher dose of folic acid.

Help and support

If you have a child with spina bifida, or if you've been diagnosed with the condition yourself, you may find it helpful to speak to other people affected by spina bifida.

Shine, the spina bifida and hydrocephalus charity, can provide you with details about local support groups and organisations.

Symptoms

pina bifida can cause a wide range of symptoms, including problems with movement, bladder and bowel problems, and problems associated with hydrocephalus (excess fluid on the brain).

The severity of the symptoms of spina bifida varies considerably, largely depending on the location of the gap in the spine.

A gap higher up the spine is more likely to cause paralysis of the legs and mobility difficulties compared with gaps in the middle or at the base of the spine, which may only cause continence issues.

A baby is more likely to have learning difficulties if they develop hydrocephalus.

Movement problems

The brain controls all the muscles in the body with the nerves that run through the spinal cord. Any damage to the nerves can result in problems controlling the muscles.

Most children with spina bifida have some degree of weakness or paralysis in their lower limbs. They may need to use ankle supports or crutches to help them move around. If they have severe paralysis, they'll need a wheelchair.

Paralysis can also cause other, associated problems. For example, as the muscles in the legs aren't being used regularly, they can become very weak.

As the muscles support the bones, muscle weakness can affect bone development. This can cause dislocated or deformed joints, bone fractures, misshapen bones and an abnormal curvature of the spine (scoliosis).

Bladder problems

Many people with spina bifida have problems storing and passing urine. This is caused by the nerves that control the bladder not forming properly. It can lead to problems such as:

urinary incontinence

urinary tract infections (UTIs)

hydronephrosis – where one or both kidneys become stretched and swollen due to a build-up of urine inside them

kidney scarring

kidney stones

Due to the risk of infection, the bladder and kidneys will need to be regularly monitored. Ultrasound scans may be needed, as well as tests to measure the bladder's volume and the pressure inside it.

Bowel problems

The nerves that run through the spinal cord also control the bowel and the sphincter muscles that keep stools in the bowel.

Many people with spina bifida have limited or no control over their sphincter muscles and have bowel incontinence.

Bowel incontinence often leads to periods of constipation followed by episodes of diarrhoea or soiling.

Hydrocephalus

Some babies with spina bifida have hydrocephalus (excess fluid on the brain), which can damage the brain and cause further problems.

Many people with spina bifida and hydrocephalus will have normal intelligence, although some will have learning difficulties, such as:

a short attention span

difficulty solving problems

difficulty reading

difficulty understanding some spoken language – particularly fast conversations between a group of people

difficulty organising activities or making detailed plans

They may also have problems with visual and physical co-ordination – for example, tasks such as tying shoelaces or fastening buttons.

Some babies have a problem where the lower parts of the brain are pushed downwards towards the spinal cord. This is known as type 2 Arnold-Chiari malformation and is linked to hydrocephalus.

Other problems

Other problems associated with spina bifida include:

skin problems – reduced sensation can make it difficult to tell when the skin on the legs has been damaged – for example, if the skin gets burnt on a radiator; if a person with spina bifida injures their legs without realising, the skin could become infected or an ulcer could develop; it's important to check the skin regularly for signs of injury

latex allergy – people with spina bifida can develop an allergy to latex; symptoms can range from a mild allergic reaction – watery eyes and skin rashes – to a severe allergic reaction, known as anaphylactic shock, which requires an immediate injection of adrenalin; tell medical staff if you or your child is allergic to latex

Causes

It's not known what causes spina bifida but a number of things can increase the risk of a baby developing the condition.

Lack of folic acid

Not having enough folic acid during pregnancy is one of the most important factors that can increase your chances of having a child with spina bifida.

Folic acid (also known as vitamin B9) occurs naturally in some foods, such as broccoli, peas and brown rice. It's also added to foods, such as some breakfast cereals. Folic acid tablets are available from pharmacies and supermarkets, or your GP may be able to prescribe them for you.

It's estimated that taking folic acid supplements before you conceive and while you're pregnant may prevent up to 7 out of 10 cases of neural tube defects, such as spina bifida.

It's still unclear how folic acid helps prevent spina bifida. It's likely that folic acid is needed for important biochemical reactions in the body.

Family history

Having a family member with a neural tube defect, such as spina bifida, increases your chances of having a baby with spina bifida.

If you've previously had a child with spina bifida, your chance of having other children with the condition is significantly increased – from less than 1 in 1,500 to around 1 in 25.

If you have a family history of spina bifida, it's very important that you take high-dose folic acid, prescribed by your GP before you become pregnant, and for at least the first 12 weeks of pregnancy.

Medication

Taking certain medications during pregnancy has been linked to an increased risk of having a baby with spina bifida or other birth defects.

Valproate and carbamazepine are medications linked to spina bifida. They're often used to treat epilepsy, and some mental health conditions, such as bipolar disorder.

Doctors will try to avoid prescribing these medications if there's a chance you could get pregnant while taking them, but they may be needed if the alternatives aren't effective.

It's advisable to use a reliable form of contraception if you need to take one of these medications and aren't trying to get pregnant.

Tell your doctor if you're thinking about trying for a baby and you need to take one of these medications. They may be able to lower the dose and prescribe folic acid supplements at a higher than normal dose, to reduce the risk of problems.

If you're not sure whether a medication could affect your pregnancy, check with your doctor, midwife or pharmacist before taking it. Never stop taking a prescribed medication unless your GP or another healthcare professional responsible for your care advises you to.

Genetic conditions

Very rarely, spina bifida can occur alongside a genetic condition such as Patau's syndrome, Edwards' syndrome or Down's syndrome.

If your baby is found to have spina bifida and it's thought they may also have one of these syndromes, you'll be offered a diagnostic test, such as amniocentesis or chorionic villus sampling that can tell for certain if your baby has one of these genetic conditions.

Other risk factors

Other risk factors for spina bifida include:

obesity – women who are obese (have a BMI of 30 or more) are more likely to have a child with spina bifida than those of average weight

diabetes – women with diabetes may have an increased risk of having a child with spina bifida

Treatment

If your child is diagnosed with spina bifida, they'll be referred to a specialist team who will be involved in their care.

A care plan may be drawn up to address your child's needs and any problems they have. As your child gets older, the care plan will be reassessed to take into account changes to their needs and situation.

There are several different treatments for various problems spina bifida can cause. These are described below.

Initial surgey to repair the spine

In babies with spina bifida, nerves and membranes can push out of an opening in the spine and form a sac. This damages the nerves and can lead to serious infections, so your baby will usually have surgery to repair the spine within 48 hours of birth.

During surgery, the surgeon will put the spinal cord and any exposed tissues or nerves back into the correct place. The gap in the spine is then closed and the hole sealed with muscle and skin.

Although this will repair the defect, unfortunately it can't reverse any nerve damage.

Treating hydrocephalus

Surgery is usually needed if your child has hydrocephalus (excess fluid on the brain). The surgeon will implant a thin tube called a shunt to drain away excess fluid to another part of the body, usually the tummy.

In most cases, the shunt remains in place for the rest of the child's life. Further surgery may be needed if:

the shunt becomes blocked or infected

the child grows out of the shunt and needs a larger one

Physiotherapy

Physiotherapy is an important way of helping someone with spina bifida to become as independent as possible. The main aim is to help with movement, prevent deformity, and stop the leg muscles weakening further.

This may involve daily exercises to help maintain strength in the leg muscles, as well as wearing special splints to support the legs.

Occupational therapy

Occupational therapy can help people find ways to carry out everyday activities and become more independent.

An occupational therapist can help work out practical solutions to problem areas such as getting dressed. They may for example provide equipment, such as handrails, to make the activity easier.

Mobility aids

People who are unable to use their legs at all will usually require a wheelchair. Electric wheelchairs are available, but using a manual wheelchair can help to maintain good upper body strength.

Leg braces, splints and other walking aids can be used by people who have weak leg muscles.

Treating bone and joint problems

Further corrective surgery may be needed if there are problems with bone development, such as hip dislocation or club foot (a deformity of the foot and ankle). This type of surgery is known as orthopaedic surgery.

Treating bladder problems

Many people with spina bifida have problems controlling their bladder.

urinary catheterisation – an intermittent urinary catheter is usually needed to drain urine from the bladder several times a day to help prevent infection

bladder surgery – may involve enlarging the bladder so it can hold more urine, or connecting the appendix to the bladder and making an opening in the belly so that a catheter can be used more easily

Treating bowel problems

Bowel problems, particularly constipation, are often a problem for people with spina bifida.

Treatments for bowel problems include:

laxatives – a type of medicine to help empty the bowels

suppositories and enemas – medicines put into the bottom to help stimulate the bowels and relieve constipation

anal irrigation – where using special equipment, you pump water through a tube into your bottom to clean out your bowels; this can be done at home once you've been trained in using the equipment

antegrade continence enema (ACE) – an operation to create a channel between the bowel and a small opening (stoma) on the surface of the tummy; this means liquids can be passed through the opening in the tummy to flush stools out of the bottom

colostomy – surgery to divert one end of the large bowel through an opening in the tummy; a pouch is placed over the opening to collect stools; a colostomy may be recommended if other treatments don't work

Support at school

Most children with spina bifida have a normal level of intelligence and are often be able to attend a mainstream school.

However, they may need support to help with any learning disabilities they have, as well as any physical problems, such as incontinence.

If you think your child may need extra support at school or nursery, talk to their teacher or the special educational needs co-ordinator (SENCO).